The manual by Floyd and Gardner entitled "Phaselock techniques" (2nd edition, pp. 182-183) describes a prior art phase loop demodulator comprising an input bandpass filter, a phase loop including a phase detector, a loop filter, and a voltage controlled oscillator (VCO), with a de-emphasis filter being disposed at the output from the phase loop.
In such a phase loop, any difference between the frequency (Fe) of the carrier to be demodulated and the rest frequency of the VCO (Fvco).sub.0, that may be due to VCO aging, or to drift in the carrier, . . . , gives rise to a static phase error at the output from the loop phase comparator, and consequently to:
degradation in the threshold of the demodulator; and PA1 greater sensitivity to "click" phenomena.
An object of the invention is to mitigate such drawbacks.